Light-intensity data-logger LI19

USBwith PC interfacewith screen

Overview
LI19 is a high-accuracy handheld read-out unit/data logger. It is used to make mobile measurements, for short term data logging (as a static logger), and as an accurate millivolt amplifier directly connected to a PC. LI19 can be used with a variety of sensors.

Key features
• Direct unit conversion: Displays measurements directly in W/m² by dividing the analogue voltage input by the programmed sensor sensitivity.
• Standalone logging and extended battery life: Powered by 2 standard AA batteries providing over 50 days of continuous operation, with internal storage for up to 3518 measurements.
• High-accuracy 16-bit measurement: Features 16-bit A/D conversion with an input calibration uncertainty of 0.1% across selectable voltage ranges from 6.25 to 200 mV.
• PC connectivity and user interface: Configured and managed via dedicated LI19 software over USB, enabling simple parameter setup, live PC-connected amplification, and data export.
• Comprehensive measurement logging: Records minimum, maximum, and average values over user-selectable intervals ranging from 2 to 65535 seconds.
• Broad sensor compatibility: Connects easily to heat flux sensors and pyranometers via universal 4 mm banana plug terminals with screw wire clamps.
• Field-ready transport case: Supplied in a rugged transport case with dedicated compartments to protect the logger, spare batteries, and connected sensors during field campaigns.

Applications
• Short-term mobile and field measurements of solar radiation or heat flux.
• Static standalone logging for solar irradiance monitoring or thermal research.
• Signal amplification and live read-out directly connected to a PC.
• Educational and academic demonstrations in solar energy and heat transfer physics.
• Field verification and on-site testing combined with portable sensors such as SR05 or HF03.

Specifications
• Measurands: Heat flux [W/m²] and solar radiation [W/m²]
• Input conversion: Analogue DC voltage divided by sensor sensitivity
• Rated input range: 6.25 to 200 x 10⁻³ V (selectable)
• A/D conversion: 16 bits
• Calibration uncertainty: 0.1%
• Temperature dependence: < 0.5% + 3 x 10⁻⁶ V over rated range
• Display definition: 4 digits with sign
• Display refresh rate: 1 s⁻¹
• Sample rate: 2 s⁻¹
• Storage capacity: 3518 measurements (stored as min, max, and average)
• Storage interval range: 2 to 65535 s (selectable)
• Sensor compatibility: Models SR05-A1, HFP01, SBG01, HF03, and compatible analogue millivolt sensors
• Connection to sensor: 2 x female chassis plugs for 4 mm banana plugs with screw signal wire clamps
• Connection to PC: USB 1.1 / 2.0 low speed
• System requirements: Windows XP and higher
• Battery type: 2 x AA (3 VDC internal power supply)
• Battery life: > 50 days (with fresh batteries)
• Rated operating temperature range: -10 to +40 °C
• IP protection class: IP40
• Dimensions: 70 x 146 x 25 mm (unit); 400 x 300 x 120 mm (transport case)
• Weight: 0.175 kg (net unit); 1.3 kg (including carrying case)

Included delivery and accessories
• LI19 handheld read-out unit with 2 x AA batteries installed
• 2 spare AA batteries
• LI19 configuration software
• Heavy-duty transport case with space for sensors
• LI19 product certificate
• Measurement unit marker strips
• USB interface cable